×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

IEC Conductor Colour Codes

IEC Conductor Colour Codes

IEC Conductor Colour Codes

(OP)
I am designing a control system for an international (IEC standard) customer and would like to verify the colour coding for the conductors:

3 Phase

Phase A - Black
Phase B - Red
Phase C - White
Neutral - Light Blue

Single Phase

AC Power - Black
AC Control - Red
AC Neutral - Light Blue
DC Control - Blue
Interconnect Control (externally powered) - Orange
Ground - Green/Yellow

I have seen some places that single phase colour coding is:

AC line - Brown
AC neutral - Light Blue
DC control - ????

I am a little confused in this matter - any insight would be helpful and references to specific standards are appreciated!

RE: IEC Conductor Colour Codes

Suggestion: It is stated in this Forum as:
Machine Builders and Industrial Electrical standard insulation Wire Color code for most Industrial Plants.
Blue = dc control wire (24vdc) to (120vdc).
Yellow = 120 vac from an outside power source.
Red - 120 vac control circuit.
Black = 120 vac (x1) Hot wire or 220 vac
White = 120 vac neutral wire (x2)
Green = ground wire
(x1) is the black and (x2) white wires on the output side of a Control transformer.
IEC for 120 vac
Brown = 24 to 120 vac Hot wire
Blue  = 24 to 120 vac Neutral wire
Green/Yellow Strip = Ground wire
Black = 3 phase motor wiring.
For 3 phase Motor starter (L1-L2-L3) Line source
                          (T1-T2-T3) Load side to Motor
For 3 Phase Rotation or (phasing) A= Red B=Black C= white

RE: IEC Conductor Colour Codes


In the US, internal to control cabinets, NEMA ICS-1 has established the practice of

  Black — “line and load (AC and DC) power and motor circuits”
  Red — “AC control circuits”
  Blue— “DC control circuits”

with a notation that white and green be used under their default premises-wiring applications.
  

RE: IEC Conductor Colour Codes

Be careful with this as most European countries have still their own colour codes. The colour codes have now been fully harmonised across the EU countries yet.

For example Ireland where I work the colour codes are:
 L1 – Brown
 L2 – Red
 L3 – Yellow
 Neutral – Blue
 Earth – Green/Yellow.

The proposed harmonised colour codes proposed by CENELEC are:
• Earth: Green/Yellow
• Neutral: Blue
• Phases: Brown (first phase)Black, Grey

The date fot the implementation of this harmonised code has not been announced by CENELEC yet so you should revert to the national wiring regulations of the country where the equipment will be installed.

Regards

Sean

RE: IEC Conductor Colour Codes

(OP)
FYI - received from collegue in Netherlands.

Below the colour codes we use in Europe...

3PHASE:
Phase L1                            Brown        
Phase L2                            Black 1        
Phase L3                            Black 2        
Neutral                                    Blue        
Safety- ground, instrument-ground    Green Yellow    
    
1PHASE:            
AC Power  main current -            Brown        
AC Control - Switched main current,
230VAC controlling current              Black        
Neutral                                    Blue        
Safety- ground, instrument-ground    Green Yellow
        
Other AC Voltage:            
From save altered Current (24VAC, 42VAC ……)    Red
Common from save altered current            White    
Safety- ground, instrument-ground        Green Yellow

DC Voltage:            
Phase from save direct current (plc inputs etc)    Orange    
Common from save direct current                    Green    
Measurement signals                            Yellow    
Voltage initiated in relay assembly            Purple    
Hazards direct current                            Grey    
Safety- ground, instrument-ground            Green Yellow        

RE: IEC Conductor Colour Codes

The European standard most often referenced is called EN60204.  I believe it existed as an IEC standard prior to the CE Low Voltage directive.  It seems to have universal acceptance if not "official" acceptance. Most of your questions on color codes are covered in this.  I don't have any knowledge about efforts to harmonize the colors for 3-ph. systems.  It's best to check with your customer on this if they are not part of the EU.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources